Functionalization of nanodiamond with vitamin E TPGS to facilitate oral absorption of curcumin

Biological and computational assessments of thiazole derivative-reinforced bile salt enriched nano carriers: a new gate in targeting SARS-CoV-2 spike protein

There is merit in investigating novel therapeutic molecules that hit vital targets during the viral infection cycle i.e. disrupting the interaction between SARS-CoV-2's spike glycoprotein and the host's angiotensin converting enzyme 2 (ACE2) receptor, potentially offering new avenues for treatment. Accordingly, lipid-based vesicular systems like liposomes or niosomes are frequently utilized to overcome these hurdles. Thus, chemically synthesized compounds were encapsulated within PEGylated bilosomes (PBs) to improve their solubility and intestinal permeability, thereby enhancing their anti-SARS-CoV-2 effectiveness. The formulae were prepared according to 23 full factorial design which was also used to explore the impact of the change in predetermined formulation variables on the properties of the prepared vesicles (entrapment efficiency EE%, particle size PS, and zeta potential ZP). Additionally, the optimized formula (F4) which is composed of 3% bile salt (BS), 40 mg 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPE) and sodium deoxycholate (SDC) as a bile salt, was selected as an optimum formula with desirability value 0.674 using Design Expert® software. Both the in vitro release and ex vivo experiments results confirmed the significant superiority of the F4 over the drug dispersion. Both cytotoxicity and anti-SARS-CoV-2 activity of all examined compound-loaded PBs (PB3a-PB3g) were assessed in Vero E6 cells via MTT assay. Both compounds PB3c and PB3g displayed the highest IC50 values (0.71 and 1.25 μg mL-1, respectively) ensuring their superior antiviral potential. Moreover, it was revealed that PB3c demonstrated more than 80% virucidal activity and over 80% inhibition of viral adsorption with little effect on the viral replication ∼(5-10%). Moreover, molecular docking and dynamic studies were conducted to pursue the binding affinities of the investigated compounds towards the ACE2 target of the SARS-CoV-2 spike protein, assuring their feasible inhibitory potential. Collectively, the investigated compound-loaded PBs can be treated as promising lead drug delivery panels for COVID-19 management.

'Poly phenolic phytoceutical loaded nano-bilosomes for enhanced caco-2 cell permeability and SARS-CoV 2 antiviral activity': in-vitro and insilico studies

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) predisposed to the emergence of worldwide catastrophe that impels the evolution of safe and effective therapeutic system. Polyphenols as resveratrol (RSV) exhibit a well evidenced antiviral activity. Unfortunately, like most phenolic nutraceuticals, RSV suffers from restrained solubility and massive degradation in GIT and liver which in turn prohibit its clinical use. Herein, PEGylated bilosomes (PBs) contain PEGylated edge activator along with the traditional components as (Span 60, cholesterol and bile salts) were proposed to boost both permeability and bioavailability of RSV. The investigation of the prominent effect of the diverse variables on the characteristics of the vesicles and picking of the optimum formula were conducted via construction of 2³ factorial experiment. The appraisal of the formulae was conducted on the basis of entrapment efficiency percent (EE%), particle size (PS) and zeta potential (ZP). In addition, the spherical shaped optimal formula (F5) exhibited EE% of 86.1 ± 2.9%, PS of 228.9 ± 8.5 nm, and ZP of -39.8 ± 1.3 mV. The sorted optimum formula (F5) exhibited superior dissolution behaviors, and boosted Caco-2 cells cellular uptake by a round 4.7 folds relative to RSV dispersion. In addition, F5 demonstrated a complete in vitro suppression of SARS-CoV-2 at a concentration 0.48 μg/ml with 6.6 times enhancement in antiviral activity relative to RSV dispersion. The accomplished molecular modeling heavily provided proof for the possible interactions of resveratrol with the key residues of the SARS-CoV2 Mpro enzyme. Finally, F5 could be proposed as a promising oral panel of RSV for curation from SARS-CoV-2 infection.

Investigating the superiority of chitosan/D-alpha-tocopheryl polyethylene glycol succinate binary coated bilosomes in promoting the cellular uptake and anti-SARS-CoV-2 activity of polyphenolic herbal drug candidate

The evolution of a safe and effective therapeutic system to conquer SAR-CoV-2 infection deemed to be a crucial worldwide demand. Curcumin (CUR) is a phytomedicinal polyphenolic drug that exhibited a well-reported anti-SAR-CoV-2. However, the therapeutic activity of CUR is hindered by its poor intestinal permeability and diminished aqueous solubility. Therefore, this study strived to develop D-alpha-tocopheryl polyethylene glycol succinate (TPGS) bilosomes (TPGS-Bs) adopting 23 full factorial designs to improve solubility and intestinal permeability of CUR, hence boosting its anti-SARS-CoV-2 activity. Eight experimental runs were attained considering three independent variables: soybean phosphatidylcholine amount (mg) (SPC amount), bile salt amount (mg) (BS amount), and TPGS amount (mg). The optimum formula (F4) exhibited EE % (88.5 ± 2.4 %), PS (181.5 ± 21.6 nm), and ZP (-34.5 ± 3.7 mV) with desirability value = 0.739 was picked as an optimum formula. Furthermore, the optimum formula (F4) was extra coated with chitosan (CS) to improve permeability and anti-SAR-CoV-2 activity. Caco-2 cell uptake after 2 hr revealed the superiority of CS-F4 and F4 by 6 and 5 folds relative to CUR dispersion, respectively. Furthermore, CS-F4 exhibited a significantly higher anti-SARS-CoV-2 activity with IC50 (0.24 µg/ml) by 8.3 times than F4 (1.99 µg/ml). Besides, the mechanistic study demonstrated that the two formulae imparted antiviral activity by inhibiting the spike protein by virucidal potentialities. In addition, the conducted molecular docking and MD simulations towards the SARS-CoV-2 Mpro enzyme confirmed the interaction of CUR with key residues of the virus enzymes. Based on the preceded, CS-F4 could be assumed to be used to effectively eradicate SARS-CoV-2 infection.

Therapeutic Nanodiamonds Containing Icariin Ameliorate the Progression of Osteoarthritis in Rats

In present study, icariin (ICA)/tannic acid (TA)-nanodiamonds (NDs) were prepared as follows. ICA was anchored to ND surfaces with absorbed TA (ICA/TA-NDs) and we evaluated their in vitro anti-inflammatory effects on lipopolysaccharide (LPS)-activated macrophages and in vivo cartilage protective effects on a rat model of monosodium iodoacetate (MIA)-induced osteoarthritis (OA). The ICA/TA-NDs showed prolonged release of ICA from the NDs for up to 28 days in a sustained manner. ICA/TA-NDs inhibited the mRNA levels of pro-inflammatory elements, including matrix metalloproteinases-3 (MMP-3), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), and increased the mRNA levels of anti-inflammatory factors (i.e., IL-4 and IL-10) in LPS-activated RAW 264.7 macrophages. Animal studies exhibited that intra-articular injection of ICA/TA-NDs notably suppressed levels of IL-6, MMP-3, and TNF-α and induced level of IL-10 in serum of MIA-induced OA rat models in a dose-dependent manner. Furthermore, these noticeable anti-inflammatory effects of ICA/TA-NDs remarkably contributed to the protection of the progression of MIA-induced OA and cartilage degradation, as exhibited by micro-computed tomography (micro-CT), gross findings, and histological investigations. Accordingly, in vitro and in vivo findings suggest that the prolonged ICA delivery of ICA/TA-NDs possesses an excellent latent to improve inflammation as well as defend against cartilage disorder in OA.

Ultra-deformable free fatty acid based nano-carriers for topical delivery of Luteolin: A potential paradigm for management of Methicillin-Resistant Staphylococcus aureus skin infections

The incidences of antimicrobial resistance in particular, Methicillin-Resistant Staphylococcus aureus (MRSA) have increased during the last two decades. However, conventional dosage forms are unable to evade the barrier effect of the stratum corneum to permit deep penetration of the skin to resolve deep skin infections. There is, therefore, an urgent need for an advanced drug delivery system. Thus the study reported herein was aimed to fabricate a novasome-loaded luteolin (LUT) to improve its topical delivery and to enhance its antibacterial activity. The system was investigated for the impact of the type of surfactant, stearic acid concentration (g %), cholesterol amount (mg) and Brij 52 amount (mg) on the percent entrapment efficiency, particle size, poly-dispersity index and zeta potential. Statistical optimization of these factors was conducted using the Design-Expert® software. The optimum formulation was further in-vitro characterized by release study, differential scanning calorimetry, transmission electron microscope, x-ray diffraction and antibacterial activity. Formulation F2 composed of Span 60, 0.4 g % of stearic acid, 100 mg cholesterol and 30 mg Brij 52 was selected as the optimum formula based on the highest desirability value (0.634). F2 demonstrated enhanced antimicrobial activity with lower minimum inhibitory concentrations against a panel of MRSA clinical isolates when compared to LUT dispersion. Furthermore, the F2 formula exhibited higher anti-virulence activity by effectively inhibiting biofilm formation and suppressing α-hemolysin activity in MRSA isolates. It also demonstrated improved biosafety based on cytotoxicity assessment on human skin fibroblasts (HSF). Finally, when assessed in an in vivo skin infection mouse model, the F2 formula and commercially available fusidic acid preparation significantly reduced the microbial load of infected skin lesions compared to both the negative control and LUT dispersion-treated groups. Based on the aforementioned results, the validity of novasomes as a nano-carrier to boost in vitro and in vivo anti-MRSA activity of LUT could be affirmed.

Biomedical applications of nanodiamonds: From drug-delivery to diagnostics

Advances in nanotechnology have great potential to address many unmet clinical and biomedical needs. Nanodiamonds, as a class of carbon nanoparticles with unique properties, may be useful towards a versatile range of biomedical applications from drug delivery to diagnostics. This review describes how these properties of nanodiamonds facilitate their application in different fields of biomedicine, including delivery of chemotherapy drugs, peptides, proteins, nucleic acids and biosensors. Additionally, clinical potential of nanodiamonds, with studies in both preclinical and clinical stages, is also reviewed here, highlighting the translational potential of nanodiamonds in biomedical research.

Experimental Design of D-α-tocopherol polyethylene glycol 1000 succinate Stabilized Bile Salt Based Nano-vesicles for Improved Cytotoxicity and Bioavailability of Colchicine Binding Site Inhibitor Candidates: In Vitro, In silico, and Pharmacokinetic Studies

Nowadays, conventional anticancer therapy suffers many pitfalls, including drastic side effects and limited therapeutic efficacy resulting from diminished oral bioavailability. So, in an attempt to enhance their poor solubility and oral bioavailability along with the cytotoxic activity, the developed lead compounds (C1 and C2) were loaded in D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) modified vesicles adopting thin film hydration technique. The formulations of the aforementioned candidates (F1 and F2, respectively) were elected as the optimum formula with desirability values of 0.701 and 0.618, respectively. Furthermore, an outstanding enhancement in the drug's cytotoxic activity against different cancer cell lines (MCF-7, HepG-2, MDA-MB-321, A375, and MGC-803) after being included in the nano-TPGS-modified optimum formula was noticed relative to the unformulated compounds. The formula F1 showed the best cytotoxic activities against HepG-2 with an IC₅₀ = 3 µM. Furthermore, regarding MCF-7, F1 was shown to be the most potent and protective among all the tested formulations with an IC₅₀ = 6 µM. Besides, F1 exerted the best caspase 3/7 activity stimulation (around a 5-folds increase) compared to control in the MCF-7 cell line. Notably, it was disclosedthat both C1 and C2 induced cell cycle arrest at the resting S growth phase. Moreover, C1 and C2 decreased tubulin concentrations by approximately 2-folds and 6-folds, respectively. Meanwhile, the conducted molecular docking studies ensure the eligible binding affinities of the assessed compounds. Besides, MD simulations were performed for 1000 ns to confirm the docking results and study the exact behavior of the target candidates (C1 and C2) toward the CBS.

Folic Acid-Chitosan Oligosaccharide Conjugates Decorated Nanodiamond as Potential Carriers for the Oral Delivery of Doxorubicin

Oral administration of doxorubicin (DOX) is preferred but challenged owing to poor permeability in the gastrointestinal tract (GIT), efflux of P-glycoprotein, short residence time in the intestine, and rapid hydrolysis. Herein, folic acid-chitosan oligosaccharide conjugate (FA-COS)-modified hydroxylated nanodiamond (ND-OH) was designed to enhance the oral bioavailability of DOX. The carboxyl surface of ND was modified into hydroxyl terminal group to increase the colloidal stability of the system under different pH conditions in GIT. FA-COS modification could prolong retention time, endow the drug with sustained release properties, and actively target intestinal FA receptors. In contrast to DOX/ND-OH, the particle size of DOX/ND-OH/FA-COS increased from 189.5 ± 2.8 to 224.5 ± 1.4 nm, and the zeta potential reversed from - 9.1 ± 0.2 to 14.8 ± 0.4 mV. At 48 h, DOX/ND-OH and DOX/ND-OH/FA-COS released 69.07 ± 5.70% and 35.87 ± 5.64%, respectively. FA-COS modification effectively enhanced the cytotoxicity and intracellular uptake of ND-OH/DOX by Caco-2 cells and prolonged intestinal retention in rats. The internalization of DOX/ND-OH and DOX/ND-OH/FA-COS was mainly mediated by energy-dependent clathrin- and caveolae-mediated endocytosis pathways. Pharmacokinetic study demonstrated that the AUC_0-t of DOX/ND-OH and DOX/ND-OH/FA-COS was enhanced by 3.94- and 6.08-fold compared to DOX solution, respectively. These results illustrated that DOX/ND-OH/FA-COS could be an effective strategy to enhance the oral bioavailability of DOX.

The Antibacterial Effect, Biocompatibility, and Osteogenesis of Vancomycin-Nanodiamond Composite Scaffold for Infected Bone Defects

Purpose

The repair and treatment of infected bone defects (IBD) is a common challenge faced by orthopedic clinics, medical materials science, and tissue engineering.

Methods

Based on the treatment requirements of IBD, we utilized multidisciplinary knowledge from clinical medicine, medical materials science, and tissue engineering to construct a high-efficiency vancomycin sustained-release system with nanodiamond (ND) and prepare a composite scaffold. Its effect on IBD treatment was assessed from materials, cytology, bacteriology, and zoology perspectives.

Results

The results demonstrated that the Van-ND-45S5 scaffold exhibited an excellent antibacterial effect, biocompatibility, and osteogenesis in vitro. Moreover, an efficient animal model of IBD was established, and a Van-ND-45S5 scaffold was implanted into the IBD. Radiographic and histological analyses and bone repair-related protein expression, confirmed that the Van-ND-45S5 scaffold had good biocompatibility and osteogenic and anti-infective activities in vivo.

Conclusion

Collectively, our findings support that the Van-ND-45S5 scaffold is a promising new material and approach for treating IBD with good antibacterial effects, biocompatibility, and osteogenesis.

Design and synthesis of new trimethoxylphenyl-linked combretastatin analogues loaded on diamond nanoparticles as a panel for ameliorated solubility and antiproliferative activity

A new series of vinyl amide-, imidazolone-, and triazinone-linked combretastatin A-4 analogues have been designed and synthesised. These compounds have been evaluated for their cytotoxic activity against MDA-MB-231 breast cancer cells. The triazinone-linked combretastatin analogues (6 and 12) exhibited the most potent cytotoxic activity, in sub-micromolar concentration compared with combretastatin A-4 as a reference standard. The results of β-tubulin polymerisation inhibition assay appear to correlate well with the ability to inhibit β-tubulin polymerisation. Additionally, these compounds were subjected to biological assays relating to cell cycle aspects and apoptosis induction. In addition, the most potent compound 6 was loaded on PEG-PCL modified diamond nanoparticles (PEG-PCL-NDs) and F4 was picked as the optimum formula. F4 exhibited enhanced solubility and release over the drug suspension. In the comparative cytotoxic activity, PEG-PCL modified F4 was capable of diminishing the IC50 by around 2.89 times for nude F4, while by 3.48 times relative to non-formulated compound 6.

Evaluation and antitumor mechanism of functionalized chitosan-based polymeric micelles for oral delivery of paclitaxel

D-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS)-modified carboxymethyl chitosan-rhein (TCR) polymeric micelles (PMs) self-assembled by TCR conjugate were constructed for oral delivery of paclitaxel (PTX). PTX-loaded TCR PMs with a drug loading capacity of 47.52 ± 1.65 % significantly improved the intestinal absorption and oral bioavailability of PTX. TCR PMs loaded with PTX displayed time- and concentration-dependent cytotoxicity in Caco-2, MCF-7 and Taxol-resistant MCF-7 (MCF-7/Taxol) cells. In MCF-7/Taxol cells, PTX-loaded TCR PMs promoted apoptosis and changed cell cycle, and TCR conjugate exhibited a P-gp inhibition ability and caused ATP depletion. Moreover, confocal imaging of intestinal sections, Caco-2 cell uptake assay and in vivo bioimaging using environmental response fluorescence probe suggested that TCR PMs loaded with drugs can be absorbed as a whole through the intestinal epithelium after oral administration, enter systemic circulation, and then get to the tumor site. Remarkably, PTX-loaded TCR PMs displayed a significant antitumor effect in H22 tumor xenograft mice and the MCF-7 or MCF-7/Taxol xenograft zebrafish model, which was related to the inhibitory function of TCR conjugate for P-gp activity and P-gp and MDR1 expression. Functionalized TCR PMs are expected to improve the oral therapeutic efficacy of poorly water-soluble antitumor drugs and treat drug-resistant tumors.

Design, Green Synthesis and Tailoring of Vitamin E TPGS Augmented Niosomal Nano-Carrier of Pyrazolopyrimidines as Potential Anti-Liver and Breast Cancer Agents with Accentuated Oral Bioavailability

VEGF plays a crucial role in cancer development, angiogenesis and progression, principally liver and breast cancer. It is vital to uncover novel chemical candidates of VEGFR inhibitors to develop more potent anti-breast and anti-liver cancer agents than the currently available candidates, sorafenib and regorafenib, that face resistance obstacles and severe side effects. Herein, nine pyrazolopyrimidine derivatives were designed, synthesized as sorafenib and regorafenib analogues and screened for their in vitro cytotoxic and growth inhibition activities against four human cancer cell lines, namely breast cancer (Michigan Cancer Foundation-7 (MCF-7), hepatocellular carcinoma (HCC) type (HepG2), lung carcinoma (A-549) and human colorectal carcinoma-116 (HCT-116)). Among the tested compounds, compounds 1, 2a, 4b and 7 showed the uppermost cytotoxic activities against all aforementioned cell lines with IC₅₀ estimates varying from 6 to 50 µM, among which compound 7 showed the best inhibitory activity on all tested compounds. Stunningly, compound 7 showed the best significant inhibition of the VEGFR-2 protein expression level (72.3%) as compared to the control and even higher than that produced with sorafenib and regorafenib (70.4% and 55.6%, respectively). Modeling studies provided evidence for the possible interactions of the synthesized compounds with the key residues of the ATP binding sites on the hinge region and the “DFG out” motif of VEGFR-2 kinase. Collectively, our present study suggests that pyrazolopyrimidine derivatives are a novel class of anti-cancer drug candidates to inhibit VEGF-VEGFR function. Aspiring to promote constrained aqueous solubility, hence poor oral bioavailability of the developed lead molecule, 7 and 2a-charged D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) surface-coated niosomes were successfully constructed, adopting a thin film hydration technique striving to overcome these pitfalls. A 2³ full factorial design was involved in order to investigate the influence of formulation variables: type of surfactant, either Span 60 or Span 40; surfactant:cholesterol ratio (8:2 or 5:5) along with the amount of TPGS (25 mg or 50 mg) on the characteristics of the nanosystem. F2 and S2 were picked as the optimum formula for compounds 2a and 7 with desirability values of 0.907 and 0.903, respectively. In addition, a distinguished improvement was observed in the compound’s oral bioavailability and cytotoxic activity after being included in the nano-TPGS-coated niosomal system relative to the unformulated compound. The nano-TPGS-coated niosomal system increased the hepatocellular inhibitory activity four times fold of compound 7a (1.6 µM) and two-fold of 2a (3 µM) relative to the unformulated compounds (6 µM and 6.2 µM, respectively).

Formulation Design and Cell Cytotoxicity of Curcumin-Loaded Liposomal Solid Gels for Anti-Hepatitis C Virus

Backgrounds. Curcumin (CUR) is a low-molecular-weight polyphenolic substance obtained from the tuber part of Curcuma species. Anti-inflammatory and anti-hepatitis C virus (HCV) activities have been associated with CUR. However, its poor aqueous solubility and low systemic bioavailability have been the challenges in improving the therapeutic efficacy of curcumin. Aim. The study aimed to produce CUR-loaded liposomal solid gels as anti-HCV delivery systems. Parameters including the physical characteristics and the cell cytotoxicity properties were evaluated. Methods. The freeze-drying technique was applied to manufacture the CUR-loaded liposomal solid gels. Scanning electron microscopy (SEM), X-ray diffractometry (XRD), and differential thermal analysis (DTA) were involved to reveal the characteristics of the solid gels. Such characteristics were as follows: the morphology and the microscopic structure of the solid gels, the crystallinity structure of the curcumin, and the thermal properties of the mixtures. Furthermore, their cell cytotoxicity was investigated using a Huh7it cell line. Results. The SEM images confirmed that curcumin liposomes were intact and trapped in the solid gel matrix. The XRD data showed flat patterns diffractograms of the formulations, confirming the transformation of CUR from crystalline to amorphous form. The DTA thermograms showed a single melting endothermic peak at a higher temperature around 200°C, indicating a single-phase transition of the mixtures. The XRD and DTA data revealed the molecular dispersion of CUR in the developed formulations. The cytotoxicity data provided as cell cytotoxicity 50 (CC50) for all formulations were ≥25 mg. These data confirmed that the developed liposomal solid gels were not cytotoxic to Huh7it cell line, indicating that the anti-HCV activity would be through a specific pathway and not by its toxicity. Conclusion. The CUR-loaded liposomal solid gels exhibited the potential and offered an alternative dosage form to improve the therapeutic efficacy of curcumin as an anti-HCV.

Enhanced cellular uptake and cytotoxicity of vorinostat through encapsulation in TPGS-modified liposomes

Vorinostat (VOR) is known as one of the histone deacetylase inhibitors (HDACi) for cancer treatment, and the FDA approves it for cutaneous T cell lymphoma therapy. Poor solubility, permeability, and less anti-cancer activity are the main challenges for the effective delivery of VOR against various cancers. So, our team assumed that the surface-coated liposomes might improve the physicochemical properties of biopharmaceutics classification system class IV drugs such as VOR. The present study aimed to enhance the cytotoxicity and improve cellular uptake using TPGS-coated liposomes in breast cancer cells. Liposomes were fabricated by the film hydration following the probe ultra-sonication method. OR-LIPO and TPGS-VOR-LIPO showed an average particle size of 211.97 ± 3.42 nm with PDI 0.2168 ± 0.006 and 176.99 ± 2.06 nm with PDI 0.175 ± 0.018, respectively. TPGS-coated liposomes had better stability and revealed more than 80 % encapsulation efficiency than conventional liposomes. Transmission electron microscopy confirmed the TPGS coating around liposomes. Moreover, TPGS-coated liposomes enhanced the solubility and showed sustained release of VOR over 48 h. DSC and PXRD analysis also reveal an amorphous state of VOR within the liposomal formulation. MTT assay result indicates that the superior cytotoxic effect of surface-modified liposomes contrasts with the conventional and free VOR solution, respectively. Fluorescence microscopy and flow cytometry results also presented an enhanced cellular uptake of TPGS-coated liposomes against breast cancer cells, respectively. The current investigation's final results declared that TPGS-coated liposomes are promising drug carriers for the effective delivery of hydrophobic drugs for cancer therapy.

Enhanced Oral Delivery of Curcumin via Vitamin E TPGS Modified Nanodiamonds: a Comparative Study on the Efficacy of Non-covalent and Covalent Conjugated Strategies

Despite that either non-covalent or covalent attachment of hydrophilic polymers or surfactants onto nanodiamonds (NDs) could overcome the shortcomings of being a drug delivery system, it is hard to draw a definite conclusion which strategy is more effective. Hence, with the purpose of comparing the influence of different coating approach of NDs on the oral delivery efficiency of water-insoluble model drug curcumin (CUR), NDs were firstly modified with D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) via non-covalent or covalent conjugation method, and then loaded with CUR (CUR@NDs-COOH/TPGS or CUR@NDs-TPGS). In comparison with the core-shell-structured CUR@NDs-COOH/TPGS, CUR@NDs-TPGS were irregular in shape with dense TPGS film, and exhibited smaller size, more negatively potential, and higher drug loading efficiency. The covalent connection group also showed higher anti-cancer activity, cellular uptake, and permeability through the Caco-2 cell monolayers, as well as favorable distribution, penetration, and retention in rat intestines. The oral bioavailability study in rats demonstrated that CUR@NDs-TPGS showed significantly greater C_max and AUC_0-t in contrast with CUR suspension and the TPGS-coated ones, respectively. The findings illustrated that covalent grafting TPGS onto the surface of NDs possesses better efficacy and biocompatibility on oral delivery of poorly soluble drug CUR than pristine and non-covalent coated nanoparticles.

Dual variable of drug loaded micelles in both particle and electrical charge on gastric cancer treatment

Gastric cancer is a malignant tumour characterised by the uncontrolled cell growth. The incidence and mortality of gastric cancer remain high for the invasion and metastasis. We are urgently seeking a risk-free and effective treatment strategy for gastric cancer. In this study, paclitaxel and tetrandrine were encapsulated in the inner core of micelles, and DSPE-PEG₂₀₀₀-CPP and HA were modified on the micellar surface. HA/CPP modified paclitaxel plus tetrandrine micelles had a suitable particle size (90 nm) for permeating tumour tissue. The zeta potential of the targeting micelles was 8.37 mV after hydrolysis by HAase solution. Results of in vitro experiments indicated that HA/CPP modified paclitaxel plus tetrandrine micelles + HAase could enhance the intracellular uptake, inhibit the formation of neovascularization, block the process of EMT and destroy the invasion and metastasis. In vivo assays indicated that HA/CPP modified paclitaxel plus tetrandrine micelles could be selectively accumulated into tumour sites and exhibited the strong antitumor activity with negligible toxicity. These results suggested that HA/CPP modified paclitaxel plus tetrandrine micelles might provide a new strategy for treating gastric cancer.

Ratiometric co-encapsulation and co-delivery of doxorubicin and paclitaxel by tumor-targeted lipodisks for combination therapy of breast cancer

Combination therapy is a promising treatment for certain advanced drug-resistant cancers. Although effective inhibition of various tumor cells was reported in vitro, combination treatment requires improvement in vivo due to uncontrolled ratiometric delivery. In this study, a tumor-targeting lipodisk nanoparticle formulation was developed for ratiometric loading and the transportation of two hydrophobic model drugs, doxorubicin (DOX) and paclitaxel (PTX), in one single platform. Furthermore, a slightly acidic pH-sensitive peptide (SAPSP) incorporated into lipodisks effectively enhanced the tumor-targeting and cell internalization. The obtained co-loaded lipodisks were approximately 30 nm with a pH-sensitive property. The ratiometric co-delivery of two drugs via lipodisks was confirmed in both the drug-resistant MCF-7/ADR cell line and its parental MCF-7 cell line in vitro, as well as in a tumor-bearing mouse model in vivo compared with a cocktail solution of free drugs. Co-loaded lipodisks exerted improved cytotoxicity to tumor cells in culture, particularly to drug-resistant tumor cells at synergistic drug ratios. In an in vivo xenograft mouse model, the anti-tumor ability of co-loaded lipodisks was evidenced by the remarkable inhibitory effect on tumor growth of either MCF-7 or MCF-7/ADR tumors, which may be attributed to the increased and ratiometric accumulation of both drugs in the tumor tissues. Therefore, tumor-specific lipodisks were crucial for the combination treatment of DOX and PTX to completely exert a synergistic anti-cancer effect. It is concluded that for co-loaded lipodisks, cytotoxicity data in vitro could be used to predict their inhibitory activity in vivo, potentially enhancing the clinical outcome of synergistic therapy.

Nanodiamonds: Minuscule gems that ferry antineoplastic drugs to resistant tumors

Remarkable efforts are currently devoted to the area of nanodiamonds (NDs) research due to their superior properties viz: biocompatibility, minute size, inert core, and tunable surface chemistry. The use of NDs for the delivery of anticancer drugs has been at the forefront of NDs applications owing to their ability to increase chemosensitivity, sustain drug release, and minimize drug side effects. Accelerated steps towards the move of NDs from bench side to bedside have been recently witnessed. In this review, the effects of NDs production and purification techniques on NDs' final properties are discussed. Special concern is given to studies focusing on NDs use for anticancer drug delivery, stability enhancement and mediated targeted delivery. The aim of this review is to put the results of studies oriented towards NDs-mediated anticancer drug delivery side by side such that the reader can assess the potential use of NDs in clinics and follow up the upcoming results of clinical testing of NDs on animals and humans.

Novel self-nanomicellizing solid dispersion based on rebaudioside A: a potential nanoplatform for oral delivery of curcumin

Purpose

Rebaudioside A (RA) has nanocarrier characteristics that allow it to self-assemble into micelles in aqueous solutions. The purpose of this study was to determine if a self-nanomicellizing solid dispersion based on RA could be utilized as an oral nano-drug delivery system.

Materials and methods

Curcumin (Cur) served as a model hydrophobic drug, and a Cur-loaded self-nanomicellizing solid dispersion based on RA (RA-Cur) was formulated. The properties of RA-Cur in the solid state and in aqueous solution were characterized. The antioxidant activity and mechanism of RA-Cur endocytosis were also investigated. The pharmacokinetics, biodistribution in the intestinal tract, and anti-inflammation properties were also evaluated in vivo.

Results

RA-Cur could be easily fabricated, and it self-assembled into ultrasmall micelles (particle size ~4 nm) in a homogeneous distribution state (polydispersity index <0.2) when dissolved in water. Cur was readily encapsulated into RA micelles and this improved its water solubility (to 14.34±1.66 mg/mL), as well as its in vitro release and membrane permeability. The antioxidant activities of Cur in RA-Cur were also significantly improved. Biodistribution in the intestinal tract confirmed a significant enhancement of Cur absorption in the duodenum, jejunum, and ileum by encapsulation in RA-Cur, and the absorption of RA-Cur was governed by mixed transcytosis mechanisms. Pharmacokinetic tests of RA-Cur in rats revealed a dramatic 19.06-fold enhancement of oral bioavailability when compared to free Cur. More importantly, oral administration of RA-Cur could efficiently ameliorate ulcerative colitis in a mouse model induced by dextran sodium sulfate.

Conclusion

Self-nanomicellizing solid dispersions based on RA have great potential as novel oral nano-drug delivery systems for hydrophobic drugs such as Cur.

Apically targeted oral micelles exhibit highly efficient intestinal uptake and oral absorption

Introduction

Polymeric micelles (PMs) hold promise for improving solubility and oral absorption of poorly soluble drugs. Unfortunately, the oral absorption of PMs is also limited by intestinal epithelium. To improve the oral delivery efficiency of micelles, transporter-mediated micelles could enhance the transport efficiency across the epithelial barrier, and they have attracted more attention.

Methods

Peptide transporter 1 (PepT1)-mediated micelles (Val-PMs/Phe-PMs) were designed by grafting valine (or phenylalanine) onto the surface of curcumin (Cur)-loaded-D-α-tocopheryl polyethylene glycol 1000 succinate micelles (TP-PMs). The oral absorption mechanism and oral bioavailability were further investigated in vitro and in vivo.

Results

The cellular study showed that Val-PMs/Phe-PMs had a high PepT1 affinity, resulting in a higher drug uptake and transcellular transport than TP-PMs. In rats, Val-PMs/Phe-PMs exhibited higher intestinal accumulation in the apical side of the intestinal epithelium than TP-PMs, promoting drug diffusion across epithelial barrier. The oral bioavailability of Cur was significantly improved by Val-PMs/Phe-PMs, which was about 10.50- and 3.40-fold greater than that of Cur-Sol and TP-PMs, respectively.

Conclusion

PepT-1-mediated micelles, using PepT1 as a target on intestinal epithelium, have unique functions with intestine and prove promising for oral delivery of poorly water-soluble drugs.